Q1+2. When a nucleus emits an α or β particle, it changes to a new element.

1. In this ß decay equation, what are the missing numbers x and y?

	14	C		14	N	+	y	ß
	6			x			-1

• A. x=5, y=1
• B. x=5, y=0
• C. x=7, y=1
• D. x=7, y=0

2. In the above equation, a particle is missing from the right-hand side of the equation, having no mass or charge.

What is the name of this particle?

• A. A neutrino.
• B. An anti-neutrino.
• C. A neutron.
• D. An anti-neutron.

How old is the sample?

• A. 125 yrs
• B. 3000 yrs
• C. 4000 yrs
• D. 8000 yrs

4. There are 4 fundamental forces at work in nature. Which of these answers describes the range of gravity and the strong nuclear force?

5. Nuclear power stations emit a small amount of radiation into the environment, which is detectable all the time. this is called background radiation. There are many other sources.

Which of the following is NOT a source of background nuclear radiation?

• A. Cosmic rays.
• B. Radon gas from underground.
• C. Medical applications.
• D. Microwave ovens.

6. Electrons orbiting the nucleus of an atom have been found to have different levels of energy that are not continuous and have specific values depending on the element.

What word in physics is used to describe these 'non-continuous' energy levels?

• A. Packaged energy levels.
• B. Discrete energy levels.
• C. Fixed energy levels.
• D. Limited energy levels.

Q7-10. This diagram shows electron energy levels in a hydrogen atom. Only the first 4 energy levels are shown.

Emission or absorption of a photon is associated with an electron jump between energy levels.

For the following questions, only jumps between the 4 energy levels shown are considered.

(Not to scale -approximate energy level values).

7. Which energy level change will emit a photon with the highest frequency?

• A. From n = 4 to n = 1.
• B. From n = 1 to n = 4.
• C. From n = 3 to n = 4.
• D. From n = 4 to n = 3.

8. At n = ∞, which of these statements is true?

• A. The energy level of the electron is infinite, the electron is still orbiting the nucleus.
• B. The energy level of the electron is zero, the electron is still orbiting the nucleus.
• C. The energy level of the electron is zero, the electron is ionised.
• D. The energy level of the electron is infinite, the electron is ionised.

9. Cold hydrogen gas in space is subjected to a wide spectrum of radiation from the Sun. Which of these statements best describes the absorption and emission of radiation by the hydrogen gas?

• A. A wide range of a frequencies is absorbed, and a narrow range of specific frequencies re-radiated in all directions.
• B. A wide range of a frequencies is absorbed, and a wide range re-radiated in all directions.
• C. A narrow range of specific frequencies is absorbed, and a narrow range of specific frequencies re-radiated in all directions.
• D. A narrow range of specific frequencies is absorbed, and a wide range re-radiated in all directions.

10. Photons of visible light have energy of between 1.8 and 3.1 eVs. Which of the following transitions is likely to emit an infrared light photon?

• A. From n = 3 to n = 2.
• B. From n = 2 to n = 4.
• C. From n = 4 to n = 2.
• D. From n = 4 to n = 3.